PHNOM PENH—Even before a Cambodian judge sentenced land rights activist Tep Vanny to prison, her fellow campaigners said her fate had already been sealed.

Vanny, who fought the evictions of thousands of residents from lakeside land in Phnom Penh to make way for a luxury real estate project, was sentenced to 2½ years on Thursday for her role in a protest outside Prime Minister Hun Sen’s residence in 2013.

She was found guilty of inciting violence and assaulting security guards while trying to deliver a petition to Hun Sen on the land dispute.

The conviction came despite eyewitness testimony that neither Vanny or other protesters had committed acts of violence. It was criticized by campaigners as another step in a crackdown on dissent.

“The courts do not use their conscience. They just wait for orders from powerful men,” said Vanny, a mother of two in her mid-30s, during a recess before her verdict. “It’s easy to use the court. They are using my case to intimidate other people … and scare others to not protest.”

Land grabs and forced evictions are a major problem in Cambodia, with thousands of families driven from farmland or urban areas to make way for real estate developments or mining and agricultural projects.

The three security guards suing her did not testify. As a clerk read their nearly identical statements about Vanny urging protesters to violence, she held her palms together in prayer on top of her head and sobbed, shoulders shaking.

Government spokesman Phay Siphan rejected the accusation that the government was using the judiciary to hound opponents. “What the judiciary has done is based on facts and legal grounds, not on politics,” Siphan said. “The allegations are just a set-up to cause confusion that everything in Cambodia is under the control of Prime Minister Hun Sen.”

Home to 15 million people, impoverished Cambodia has a long history of disputes over land rights, many dating back to the 1970s, when the Khmer Rouge regime destroyed property records.

Between 2000 and 2014, about 770,000 Cambodians — more than 6 percent of the population — were affected by land conflicts, according to charges presented by human rights lawyers at the International Criminal Court in The Hague.

In a report last year, the nonprofit Cambodian League for the Promotion and Defense of Human Rights (LICADHO) said the lack of a publicly available land register detailing state land boundaries meant authorities could confiscate land, claiming that the affected families are living on state property.

Communities that protest their loss of land come up against authorities and corporations who respond with intimidation, violence and judicial persecution, LICADHO said in the report.

Vanny is the most prominent activist from Phnom Penh’s Boeung Kak area, which was once a large scenic lake but has now been filled in to make way for construction.

The three men who sued her are from the Daun Penh district security unit, which has a reputation for violence.

In their statements, one guard, Hor Hoeun, said he was hit on the head by a protester’s loudspeaker. Another, Uk Rotana, said he was struck by a 50-year-old woman holding a bag. The third witness claimed to have found a bag with rocks inside.

The men came to the courthouse ahead of the hearing but did not enter the courtroom. They declined to be interviewed, letting their unit chief, Kim Vutha, speak for them.

“We did not intend to use violence,” Vutha said, defending his unit against news reports, witness accounts and video footage showing them beating protesters. “The video is shot from an angle that makes us look bad.”

In the trial, defense witness Bo Chhorvy described the guards breaking the arm of one protester and knocking out three teeth of another. The protesters had only lotus flowers and loudspeakers, she told the court.

“We did not have weapons. They had shields, batons, guns — how could we commit violence upon them?” she asked.

“According to the documents, the guards were injured,” the judge responded.

Vanny’s lawyer, Ham Sunrith, said the only person the guards accused of violence in their statements was the 50-year-old woman.

“They bring no witnesses, and they point at a third person, who is not my client,” Sunrith said. “The person who committed the crime is not here in the court.”

Activists slammed the verdict.

“The judge really presided over a kangaroo court that showed no real evidence is required for a conviction,” said Phil Robertson, the Asia deputy director for Human Rights Watch. “This verdict shows once again that there is no justice in Cambodia for local rights activists struggling to defend their land and communities from rapacious development activities by Prime Minister Hun Sen and his cronies.”

Kingsley Abbott, senior international legal adviser at the International Commission of Jurists, said the fact the guards were not called to be cross-examined by the defense appeared to violate Vanny’s right to a fair trial. “The verdict is part of an escalating and systematic strategy to legally harass human rights defenders and political opponents into silence,” Abbott said.

A court spokesman said the court acts independently and fairly.

As the judge finished reading the verdict, Vanny and her supporters in court erupted into protest, shouting, “Injustice!”

Guards surrounded Vanny and rushed her out of the courtroom, and security guards wearing bulletproof vests prevented the witnesses and protesters from following her.

Outside the court on a traffic-clogged street, about 60 protesters were surrounded by dozens of security guards wearing helmets and carrying shields.

As a sedan carrying Vanny sped away from the courthouse, the witness Chhorvy ran after the car. “The court is corrupt!” she screamed as she fell to her knees at the gate of the court and cried.

Later on Thursday, videos were shared on social media of guards kicking and manhandling female protesters laying on the street in front of the courthouse.